1. Field
The present embodiments generally relate to processes for upgrading hydrocarbons. More particularly, embodiments of the present invention relate to processes for upgrading hydrocarbons using a solvent de-asphalting unit.
2. Description of the Related Art
Solvent de-asphalting (“SDA”) processes have been used to treat heavy hydrocarbons using a solvent to generate asphaltic and de-asphalted oil (“DAO”) products. The asphaltic and DAO products are typically further treated and/or processed into useful products.
Solvent deasphalting can be economically attractive when downstream treatment facilities such as hydrotreating or fluid catalytic cracking are adequately sized to process the large volume of DAO generated when treating atmospheric tower bottom residuum. The DAO produced using a solvent deasphalting unit typically contains both light and heavy hydrocarbons, and requires further processing, typically by cracking, to convert the low-value heavy hydrocarbons to high-value lighter hydrocarbons. However, cracking the entire volume of DAO requires operation of the cracker at low temperature and low severity to avoid destroying the high-value light hydrocarbons, such as kerosene and diesel oils that are present in the DAO. By restricting the cracker to low temperature/low severity operation, the conversion of heavy hydrocarbons is limited, and the overall yield of desirable high-value light hydrocarbons is compromised.
A need exists for an improved process to upgrade heavy hydrocarbons into more valuable synthetic crude oil.